N and finally tonight, our barbara walters breaking new ground. She's been in television for decades, creating one more headline today. About her plans for the future. And abc's david muir was behind the scenes with her as she announced her decision. Reporter: We were right there this morning. As a television icon took a moment to herself. Barbara walters preparing to break another headline. I'm so impressed you put on a suit and tie. This is for barbara walters. Reporter: And we ask how she's feeling. It's not how I'm feeling today. It's how I'm going to feel then, and everyone says to me, what are you going to do next? I don't know. Reporter: Everything about it has been a groun-breaking run. Back on the "today"w when they were called girls, she became co-host. The first woman to co-host the evening news. Barbara walters. Reporter: And then creating "the view." But she'll walk away from all those cameras a year from now. Today she wanted her crew to hear it from her first. Why? It's time. I want to leave while people say, we'll miss her, instead of, is she still here? People say, you lose your mentor. I didn't have any. Today, if a young woman says, i grew up watching you, or you made it a little easier, david, I think that's my legacy. Reporter: She defined in this industry the big get. Fiddel castro. Do you feel funny crossing the bay of pigs with an american? The joint interview. Egypt's anwar sadat. Israel's prime minister, menachem begin. Putin. And not long ago, her tough questions for syria's bashar al assad. But all this time, one person waiting. What does your daughter say to you about this decision? There were times when I felt i should have been with her, and i think every working mother has those days. But I think she wants me to stop working now and spend more time with her. And I will. Reporter: Backstage, the mike, the cards, the tv earpiece, and she was off. let me just say that, oh, take a breath. But in the summer of 2014, a year from now, I plan to retire from appearing on television at all. Reporter: Right there her co-hosts, her viewers, and her boss, that once delivered her the mail in 1976. Bob iger, now the ceo of disney. I was asked to deliver something to your dressing room. And I didn't think that you would be there and I barged in and there you were. I was rather embarrassed. Was I nice, I hope? You were extremely nice. You put me at ease. You asked me what my name was and what did I do and I told you. From then on you called me jim. My name is bob. Thank you, jim. It means so much. trademark humor as she embarks on her final year. We've worked with her on so many big assignments her stack of cards and notes today, as big as that first assignment for her. Let that be a lesson. She's always teaching all of us.

This transcript has been automatically generated and may not be 100% accurate.